[skorpioskorpio]

This is specifically why E-Codes (European Headlights) cut off below the horizon so that you look down into the light. It's also the reason the French took it one step further and required amber tinted bulb or reflectors or lenses in an effort to decrease the effects of night blindness and particle and bright object bounce back. E-Codes also are designed to illuminate roadside signs enough to give fair warning and keep them in the peripheral vision, aimed correctly they do not illuminate signs far down the road (not by low beam anyway) when they are in your central vision.

I wasn't aware there was specifically more reflective material in US signs, though that would explain why road signs with E-Codes seem to explode with light when they come into the beam field.